The published Flora of Pakistan is a comprehensive inventory of the plants of Pakistan, the first modern flora of more than 6,000 species from a large, relatively poorly known region of South Asia. This Pakistan Plant Database (PPD) includes all information published in the Flora volumes already in print in a searchable web-based format.

To date, this project has produced 217 volumes of the Flora, the last 16 co-published by the Missouri Botanical Garden and the University of Karachi. Many treatments have been authored by world authorities on the taxa involved, often partnered with Pakistani botanists, and the volumes are well-edited and well-received by the botanical community (Schmid 2002). The final volumes awaiting completion include those covering Scrophulariaceae s. l., the remaining tribes of Rosaceae and Asteraceae (parts of both already published), and the pteridophytes (ferns). Altogether, treatments of the remaining families will provide accounts for c. 1,100 species, published in 6—10 volumes and about 2000 pages of text. Information from these volumes will be added to the PPD as it becomes available.

Because the format of the Flora includes such extensive information, the PPD is nearly monographic in detail. Cited specimens are geo-referenced by grid system, and new collections have full GPS data. It is the only comparable database for South Asia, and is fully compatible with the Flora of China database.

Background: Geography and Floristics

Although established as an independent country only in August 1947, Pakistan occupies a position of great biogeographical and geostrategic importance, bordered by Iran on the west, Afghanistan on the northwest, China on the northeast, India on the east, and the Arabian Sea on the south (Fig. 1). Lying between 23°-37° N and 61°-81° E, Pakistan has a total land area of 804,152 square kilometers, somewhat less than twice the size of California. The altitude ranges from sea level to 8,611 m (at K2, the second highest peak on Earth), and temperature varies from well below zero in the high, glacier-clad mountains to 52°C (125°F) at Sibi in the plains. Mean annual precipitation ranges from c. 50 mm at Nok Kundi in Baluchistan to 2032 mm in the monsoonal uplands of Kashmir (Ali 1978). This great variation in elevation, temperature, precipitation, and other physical parameters has resulted in a diversity of biotic communities, and a relatively rich flora of at least 5,700 species of flowering plants (Ali 1978).

Pakistan sits astride one of the major disjunctions in the biota of southern Asia, with the line of demarcation running along the western edge of the Indus Basin and the deep dry upper Indus valley of Kohistan (Frodin 1984). This biogeographic disjunction was the mutual boundary between Boissier’s Flora Orientalis (1867-1888) and Hooker’s Flora of British India (1872-1897), the two standard floras of the late nineteenth century for Southwest and South Asia, respectively. One of the modern floras of the region, the Flora Iranica, initiated in 1963 by K. H. Rechinger (Vienna), follows this eastern boundary of Boissier’s work, and so includes Baluchistan and the N.W.F. Provinces of Pakistan. The Flora Iranica does not, however, treat plants of the rest of Pakistan, including the very rich northeastern areas.

The underlying basis of this disjunction has been explored by numerous biogeographical analyses, such as those of Stewart (1972), Zohary (1973), Ali (1978), and Hedge & Wendelbo (1978). Takhtajan (1986), summarizing much of this literature, delineated five distinct floristic provinces that extend into the territory of Pakistan (Fig. 1). Two of these provinces, the Southern Iranian and Sindian Provinces, belong to the Sudano-Zambezian Region (African Subkingdom, Paleotropical Kingdom), which extends west along the southern Arabian Peninsula through the Horn of Africa to eastern tropical Africa and across to the Atlantic coast of Mauritania, Senegal, and Guinea. The other three floristic provinces in Pakistan belong to the Irano-Turanian Region (Tethyan Subkingdom, Holoarctic Kingdom): the Northern Baluchistan and Western Himalayan Provinces in the Western Asiatic Subregion, and the Tibetan Province to the Central Asiatic Subregion. Thus, the source and affinities of the plants of southern and southwestern Pakistan are with central and eastern Africa and the coastal regions along the Arabian Sea, whereas the source and affinities of the flora in northern Pakistan are with Central Asia, from Turkey in the west to the Gobi Desert in the east. In addition, eastern Pakistan has an admixture of elements from the Indomalesian Subkingdom (Paleotropical Kingdom), and in the monsoonal forests in Azad Kashmir, one finds elements of the Eastern Himalayan Province (Eastern Asiatic Region, Boreal Subkingdom, Holarctic Kingdom).

Perhaps the dominant province, and one that includes the highest species diversity and the greatest number of endemics, is the Western Himalayan Province of the Irano-Turanian Region (Fig. 1). Takhtajan (1986) notes “that the flora of this province occupies a kind of transitional position and is a link between the ancient Mediterranean (Tethyan) and eastern Asiatic floras.” Although many genera in families such as Brassicaceae, Fabaceae, Apiaceae, Lamiaceae, and Asteraceae are endemic or subendemic in the Irano-Turanian Region, there have been relatively few recent phylogenetic studies of these groups. The detailed treatments in the Flora of Pakistan for these and other groups will facilitate and encourage phylogenetic studies, making it possible, for example, to examine the historical biogeography of this region (Morrone & Crisci 1995), to define areas of endemism, and perhaps document biogeographic ramifications of the convulsive tectonic history of South Asia. This in turn will facilitate comparisons between evolutionary radiations in the Western Himalaya and those in other mountain systems worldwide (Borgen & Jonsell 1997), or between radiations in Sind and Baluchistan with other arid areas, such as the Madrean region of southwestern North America (Katinas et al., 2004).

The flora of Pakistan includes no endemic families, and only three endemic genera (Douepia in Brassicaceae, Stewartiella in Apiaceae, and Decalepidanthus in Boraginaceae). According to our present knowledge, there are some 203 endemic species, or about 4% of the flora (Ali 1978). Many of these endemic species are found in the montane regions of northern Pakistan, particularly in the Chitral and Kashmir districts, and in northern Baluchistan. However, these regions are particularly poorly known and likely to be sources of considerable numbers of new and possibly endemic species (Chaudhri 1977, Frodin 1984).

Stewart (1972, 1982), Hedge (1991), and others have reviewed the history of botanical exploration in Pakistan fairly extensively. Starting in 1820 with an expedition to Kashmir by William Moorcroft, many European (mainly British) botanists visited Pakistan, eventually collecting plants from most parts of the country. The coverage was modest in the mountainous areas in the north, inhabited by often-hostile tribes and naturally inhospitable as the nexus of the Hindu Kush, Karakoram, and Himalayan ranges. The results of these collecting activities contributed to the two great floras of the region, the Flora Orientalis (Boissier 1867-1888) and the Flora of British India (Hooker 1872-1897). Collecting continued in the early twentieth century, rendering those 19th century floras progressively out-of-date. One important aspect about the collections made in Pakistan prior to the country’s establishment in 1947 is that virtually all of them are housed either in Europe (mainly BM, E, and K) or in India, at Calcutta or Dehra Dun, in all cases relatively inaccessible to botanists in Pakistan (Stewart, 1972). The largest plant collection in Pakistan in 1947 was that developed by Stewart at Gordon College in Rawalpindi.

Background: Flora of Pakistan and the Pakistan Plant Database

Following the establishment of the new nation of Pakistan in 1947, a high priority was given to establishment of universities and a scientific infrastructure. Early in the scientific planning, the production of a Flora was seen as a priority in the area of botany. In 1960, R. R. Stewart retired from active work at Gordon College, and turned his herbarium of some 50,000 specimens over to his collaborator Prof. E. Nasir. The “Stewart Herbarium,” later presented as a gift to the nation to create the nucleus of the National Herbarium of Pakistan (Ali & Ghaffar 1991), was a critical element since most specimens collected earlier in Pakistan were kept in either European or Indian herbaria. This collection, and that established later at the University of Karachi by S.I. Ali, provided the necessary foundation to begin writing the flora. With initial funding from the U.S. Department of Agriculture, the Flora of Pakistan project was initiated in 1968, with Nasir and Ali as Joint Editors, and in 1970, the first fascicle of the Flora (Flacourtiaceae) appeared. Stewart (1972) published a preliminary checklist of the plants of the region and a guide to the developing Flora project, listing 5,783 species. Subsequent Flora treatments have not changed that overall estimate of species numbes appreciably (Ali 1991), although new treatments for individual genera/ families differ, often substantially, from those by Stewart.

By 1995 the Flora project had produced 197 treatments (one per family), ranging in size from a few pages to nearly 500 pages (Poaceae). Nasir (replaced after his death by M. Qaiser) and Ali or their colleagues and students wrote many of these treatments, while others have been completed by specialists worldwide working with them. Even though Pakistani herbaria have developed rapidly, authors have had to consult extensively with British and other foreign herbaria since they contain large historical collections and the type specimens of most species from Pakistan.

Following the expiration of USDA funding in 1995 and a period of reduced activity due to lack of funding, the Flora of Pakistan was revived following negotiations between S. I. Ali and Peter H. Raven of the Missouri Botanical Garden. In February 2000, the University of Karachi and the Missouri Botanical Garden signed an agreement to co-publish the remaining volumes of the Flora of Pakistan, According to the agreement, the University would provide edited manuscripts and print the volumes, and the Garden would provide or raise funds in support of the project, and promote and distribute the Flora outside of Pakistan. The Garden supported this proposal for several reasons: 1) it would finish a near-complete Flora of an important and insufficiently known region; 2) it connects geographically and floristically with the Flora of China project headquartered at the Garden (many taxa in common, often requiring a coordinated approach); 3) it provides the best opportunity to develop a database for plants of South Asia, able to interface with databases for China and elsewhere and serve Pakistan as an important biodiversity management tool; 4) the project serves as a focus for botanical research in Pakistan, providing training, research, and employment opportunities for indigenous botanists; and 5) it supports new botanical exploration and collecting in Pakistan, and provides a potential source of new specimens from that region, which is poorly represented in American herbaria.

The development of the electronic database of all plants in Pakistan was a logical and necessary extension of the project. No other floras in the south Asian region are available electronically, nor are any likely to be available in the near future. A comprehensive and accessible on-line flora of Pakistan is an essential step toward understanding the plants of South Asia generally. Information from Pakistan, especially in an accessible databased form, is particularly useful in relation to other floristic projects such as the Flora of China, the Flora Malesiana, and ongoing work in India and in the central Asian region. Local published floras exist for many parts of Pakistan (Stewart 1982), but the Flora of Pakistan supersedes them. The Flora of Afghanistan (Kitamura 1960) is actually a synoptical checklist of limited scope, covering only the results of expeditions to the Karakoram and Hindu Kush by Japanese botanists in 1955. A later report from the same expedition (Kitamura 1964) enumerated plants from the part of the region in Pakistan. This region where the Western Himalayas meet the Karakorams and the Hindu Kush in northern Pakistan and the northern Baluchistan region are both rich in endemic plants, and many genera of agricultural and horticultural importance occur in Pakistan, yet our knowledge of them and access to information about them is limited at the present time.

In format, the Flora of Pakistan is detailed and informative: for families and genera, it includes full synonymy and descriptions, notes, and keys; for species, full or at least regional synonymy, with usage from all regional floras, substantial descriptions, illustrations of selected species, type information, lists of vouchered specimens examined that are keyed to a 2° x 2° grid system for locating them, geographical and ecological distributions, phenology, and notes regarding unusual features and/or ethnobotanical uses. Duke (1991) noted that Stewart’s (1972) Catalogue includes at least 100 “promising phytomedicinal species,” and discussed ways in which these species, already present, might be developed for commercially viable agriculture in Pakistan.

Nasir (1991) conservatively estimated that 580-650 plant species (c. 12% of the flora) are threatened or endangered, but suggested that this number would increase when work on the Flora is completed. He cited habitat destruction, over-exploitation of economic plants, introduction of alien species, and pollution as the major causes for this threat. Nasir (1991), Sulaiman et al. (1991), and others suggest that awareness of the problems is widespread, but that additional knowledge and information is critical if the problems are to be addressed and solutions found.

In terms of issues related to conservation and environmental threats, Pakistan faces many challenges. Pakistan has a human population of 187,342,721 (July 2011 est., ranked 6th largest in the world), according to The World Factbook (https://www.cia.gov/library/publications/the-world-factbook/geos/pk.html). Because some areas of Pakistan, especially the arid Baluchistan plateau in the southwest and the mountainous north, are rather sparsely populated, this large population is heavily concentrated in the Indus Valley. The environmental impact of this huge human population and the very long history of human occupation of the Indus Valley (home to a highly developed urban civilization at least 5,000 years ago) present special challenges. Many of the most pressing environmental issues in Pakistan involve water, i.e., water pollution from raw sewage, industrial wastes, and agricultural runoff, and shortages of potable water for a majority of the populace. Other major environmental problems – deforestation, soil erosion, desertification, and climate change-induced variation in rainfall and snowpack – are also closely tied to water use and availability.

In order to begin to address these problems, Pakistan needs good information about its natural resources. A Flora based on all available plant collections, at least partially georeferenced, and on the most current taxonomy and phylogeny of those plants is an essential first step to understanding, managing, and preserving the biodiversity of any area. Because plants fundamentally define terrestrial communities, a Flora forms the foundation to which inventories of animals, fungi, etc., can be added. Completion of the Flora of Pakistan will provide scientists and government officials with critical information for management of their resources. Because the database resulting from this project includes geographical information, it can be used with data on soil types, precipitation, and other parameters to address questions such as what intact habitats should have highest priority for conservation, what types of plants should be used in restorations for erosion control, reforestation, etc., and other conservation issues.

The Missouri Botanical Garden and the principal investigators on this project gratefully acknowledge the generous support from the U.S. National Science Foundation, the Andrew W. Mellon Foundation, the Taylor Family Fund, the U.S. Department of Agriculture, and the Pakistan-US Science and Technology Cooperation Program 2009 (funded through the U.S. Agency for International Development). The PIs also gratefully acknowledge the support of our institutions, the Missouri Botanical Garden and the University of Karachi.

For more information, please contact the coordinator of the Pakistan project at the Missouri Botanical Garden, Peter Hoch (peter.hoch@mobot.org).